Hi I have a pitcher and glass set that i am trying to find out who made it and when it was made. The pitcher has a ground and polished pontil, the base of each item is triangular which carries on up the walls of each piece though the glass shape becomes more circular at the top of the pitcher and where each glass or tumbler becomes wider. The texture and design of the glass is similar to Tapio Wirkkala, Iittala glass in the Aslak range. Can anyone help me please? Thanks Chris

Thanks for your replies The photos don't show the brightness of the glow that well as they are a bit brighter than the pics show, the tube is playing up :/ My understanding of manganese (I think) is that manufacturers use it to strip out the greenish tinge in glass or use it in higher concentrates to make amethyst coloured glass, but I don't know what else it's used for? I also thought that manganese came under the uranium glass description like custard, jadeite and vaseline glass?

The significant feature of Uranium glass (completely avoiding the American use of the term "vaseline" which is originally merely a descriptive expression) is that it is radioactive. It emits (weak) gamma radiation, it will make a geiger counter go noisy, it will scintillate a scintillation counter.Uranium glass beads have been known to set off the alarms when worn by a visitor to Sellafield.

Custard and jadeite are again descriptive terms for opaque sorts of glass, custard being whitish or yellowy, jadeite being greeny; thay may or might not contain Uranium.

You are right about what manganese is/was used for but it is also found in older coloured glass. Why I don't know; possibly some coloured glass recipes involved adding to clear glass recipes rather than taking the unnecessary stuff out.

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I also thought that manganese came under the uranium glass description like custard, jadeite and vaseline glass?